Numbers k such that the period of the continued fraction for sqrt(k) contains exactly 21 ones.

Terms

a(0) =2575a(1) =8383a(2) =9919a(3) =11659a(4) =11771a(5) =13375a(6) =14999a(7) =16891a(8) =17875a(9) =18067a(10) =18232a(11) =18415a(12) =20087a(13) =22355a(14) =24568a(15) =27083a(16) =27783a(17) =29727a(18) =34867a(19) =35875a(20) =38056a(21) =40067a(22) =41987a(23) =42319a(24) =44063a(25) =44455a(26) =46343a(27) =48168a(28) =48216a(29) =50856